The present invention relates generally to fastening systems. In particular, the present invention relates to a screw for penetrating and securing a workpiece.
In construction and furniture building involving wood products, the use of alternative materials is becoming more common. Some alternative materials are made entirely from post-consumer polyethylene waste such as bottles and other recycled plastics. Other alternative materials are manufactured by mixing wood and other materials such as glass, steel, and carbon fibers with a suitable binder to vary the characteristics of the final material. Materials alternative to wood are used to construct everything from cabinets to decks. Such alternative materials are made by various processes. For example, alternative material lumber may be made by blending recycled plastic resins with sawdust and extruding the blended mixture into standard lumber sections.
Such alternative materials have many advantages over wood. The alternative materials are often stronger and more durable then even pressure treated lumber. Many materials also offer better resistance to moisture, corrosive substances, termites and other insects, and other environmental strains that often prove to be detrimental to wood.
The use of standard fasteners with these alternative materials, however, may produce unwanted results. Screws are commonly used to affix one workpiece to another. However, some of the above mentioned alternative materials may not compress as readily as wood to accommodate the added volume of the inserted screw. With respect to some of the above-mentioned alternative materials, insertion of the screw, particularly if there is no pre-drilled hole to accommodate the screw, can cause remnants or shavings to be cut, extruded, or otherwise removed from the hole made by the screw. Such alternative materials may be referred to as “remnant-producing” materials, and may include materials in addition to the alternative materials mentioned above. Some of the remnants may remain attached to the material or held to the material by the screw, and extend above the material surface. These remnants then have to be removed by sanding or other methods. A common way to reduce this problem is to pre-drill holes in the locations where a screw-type fastener must be inserted. This technique is laborious and time consuming. What is needed is a fastener adapted for use with a remnant-producing material where insertion of the fastener, particularly without pre-drilling holes, leaves a smoother surface on the remnant-producing material, reducing or eliminating remnants.